Generally, the use of chemical fertilizers and agricultural pesticides has been continuously increased to increase agricultural production output; however, it also had dangerous impacts on the ecosystem by causing soil acidification, soil depletion, soil and water contamination, and the like. In order to resolve such problems, efforts have been made by the Korean government to place more importance on environment-friendly crops by launching a policy which reduces 40% of chemical fertilizers and agricultural pesticides usage by 2013. Also, in private sector, environment-friendly agriculture techniques, such as organic farming, soil fertility improvement technologies, etc., have been developed and practiced, thereby heeding the growing demands of safe agricultural products by the consumers, and thus, eventually contributing to an increase in income of farmers.
Despite efforts made by the government and the private sector, most of the farmers are small-scale farmers who make a living by selling what they harvest from their small lands, and thus an indiscriminate use of livestock manure and compost to increase production are prevalent and over-exploitation of natural resources in soil are continued. Such trends had caused salinization and replant failure in many areas, and caused great difficulties to many farmers. As a part of a solution to this problem, an effective method is suggested to promote plant growth by assisting photosynthesis without relying on chemical fertilizers or relentlessly using organic matters.
Meanwhile, similar to the field of agriculture, synthetic antibiotics such as penicillin, bacitracin and the like have been widely used as a feed additive since 1950s to promote growth of young livestock, as well as to improve feedstuff efficiency and production efficiency of livestock product.
Generally, the mechanism of action of antibiotics is known to promote growth of young livestock by eliminating pathogenic bacteria in the intestines, e.g., Salmonella, E. coli, Clostridium, etc., by destroying their cell walls, and thinning intestinal absorptive cells of the small intestine in livestock to increase the nutrient absorption rate.
Several issues have been brought up regarding the use of antibiotics including antibiotic accumulation possibilities, adverse side effects on body's immune system when ingested by human, and the like. Nowadays, people are becoming health-conscious and, as a result, their concerns over adverse side effects of antibiotics on body's immune system due to indiscriminate use of antibiotics caused their preferences of livestock products to shift from quantity to quality. Accordingly, there is a trend of prohibiting or restricting the use of synthetic antibiotics to livestock in some countries centering on European countries including Sweden, etc. Thus, there is a growing demand for an alternative to synthetic antibiotics; and research and development of safe candidate materials and effectiveness study thereof still remain as an issue needs to be addressed in the livestock industry.